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dc.contributor.advisor Velempini, M. Ngomane, Issah 2019-03-06T10:02:47Z 2019-03-06T10:02:47Z 2018
dc.description Thesis ( M.Sc. ( Computer Science)) -- University of Limpopo, 2018 en_US
dc.description.abstract Dynamic spectrum access enabled by cognitive radio networks is envisioned to address the problems of the ever-increasing wireless technology. This innovative technology increases spectrum utility by allowing unlicensed devices to utilise the unused spectrum band of licenced devices opportunistically. The unlicensed devices referred to as secondary users (SUs) constantly sense the spectrum band to avoid interfering with the transmission of the licenced devices known as primary users (PUs).Due to some environmental challenges that can interfere with effective spectrum sensing, the SUs have to cooperate in sensing the spectrum band. However, cooperative spectrum sensing is susceptible to the spectrum sensing data falsification (SSDF) attack where selfish radios falsify the spectrum reports. Hence, there is a need to design a defence scheme that will defend the SSDF attack and guaranty correct final transmission decision. In this study, we proposed the integration of the reputation based system and the qout-of-m rule scheme to defend against the SSDF attack. The reputation-based system was used to determine the trustworthiness of the SUs. The q-out-of-m rule scheme where m sensing reports were selected from the ones with good reputation and q was the final decision, which was used to isolate the entire malicious nodes and make the correct final transmission decision. The proposed scheme was implemented in a Cognitive Radio Ad Hoc Network (CRAHN) where the services of a data fusion centre (FC) were not required. The SUs conducted their own data fusion and made their own final transmission decision based on their sensing reports and the sensing reports of their neighbouring nodes. Matlab was used to implement and simulate the proposed scheme. We compared our proposed scheme with the multifusion based distributed spectrum sensing and density based system schemes. Metrics used were the success probability, missed detection probability and false alarm probability. The proposed scheme performed better compared to the other schemes in all the metrics. en_US
dc.description.sponsorship CSIR, NRF and, University of Limpopo research office en_US
dc.format.extent viii, 73 leaves en_US
dc.language.iso en en_US
dc.relation.requires PDF en_US
dc.subject Defence Mechanism en_US
dc.subject Mitigate en_US
dc.subject Spectrum sensing data falsification attack en_US
dc.subject Cognitive radio en_US
dc.subject Ad hoc networks en_US
dc.subject.lcsh Computer science. en_US
dc.subject.lcsh Computer networks. en_US
dc.title The design of a defence mechanism to mitigate the spectrum sensing data falsification attack in cognitive radio ad hoc networks en_US
dc.type Thesis en_US

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