The cognitive Radio paradigm has recently received considerable interest to address the so called ’spectrum scarcity’ problem. In the USA, the Federal Communications Commission recently issued the regulatory for the use of cognitive radio in the TV white space spectrum. The primary objective is the design of cognitive devices able to combine the use of spectrum sensing and GEO-location informat...

Resource allocation for secondary users is an important issue in cognitive radio networks. In our article, we introduce a resource allocation scheme for secondary users to share spectrum in a cognitive radio network. Secondary users can exploit the spectrum owned by primary links when the interference level does not exceed certain requirements. Uncertainties of channel gains pose a great impact...

Spectrum sensing in cognitive radio networks allows secondary users to sense the unused spectrum without causing interference to primary users. Cognitive radio requires more accurate sensing results from unused portions of the spectrum. Accurate spectrum sensing techniques can reduce the probability of false alarms and misdetection. In this paper, a two-stage spectrum sensing scheme is proposed...

In this paper, spectrum access in cognitive radio networks is modeled as a repeated auction game subject to monitoring and entry costs. For secondary users, sensing costs are incurred as the result of primary users’ activity. Furthermore, each secondary user pays the cost of transmissions upon successful bidding for a channel. Knowledge regarding other secondary users’ activity is limited due t...

Nous présentons une stratégie dynamique pour le choix de canaux dans un réseau radio cognitif. Notre stratégie se base essentiellement sur l’estimation de l’occupation du canal radio provoquée par l’activité des nœuds primaires plus prioritaires sur les canaux en questions. Notre technique, et grâce à une écoute permanante sur les canaux, dote les nœuds cognitifs de la capacité d’inférer les ca...

This article presents the results of researchrelated to the assessment protocol weightedcumulative expected transmission time (WCETT)applied to cognitive radio networks.The development work was based on researchdone by different authors, we simulated a network,which communicates wirelessly, using a licensedchannel, through which other nodes are notlicensed, try to transmit during a given time n...

Along with Cognitive Radio Networks are been developed, to design optimistic security mechanisms is becoming a big challenge. This paper proposes a taxonomy of attacks on Cognitive Radio Networks. This will help researches in the area to better understand the security problems and design more optimistic countermeasures. A new simulation framework for security threats has been developed to check...