Date Added: Mar 2010
In 2003, Federal Communications Commission (FCC) has released a new spectrum policy called "Interference temperature model" to improve the channel access opportunities of secondary users. Under this model, the secondary users are allowed to access the licensed spectrum simultaneously with the primary users provided that the interference at the primary receiver meets a certain threshold. The authors refer the Cognitive Radio Networks that employs this model as "Whisper CRNs" (since secondary users have to use lower transmission power to satisfy the interference constraint). In this paper, they systematically analyze the performance of whisper CRNs and compare it with the traditional CRNs, where the secondary users are not allowed to transmit when primary users are busy.