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As Cognitive Radio (CR) technology is recently emerged as a potential solution to overcome the problem of spectrum scarcity, Cognitive Wireless Mesh Networks (CogMesh) have great potential for enhancing the performance of wireless networks and meeting the demands of future generation wireless applications. By utilizing the available frequency bands that are unutilized by primary (licensed) users,...
Supporting secondary users through a collateral network dedicated to spectrum sensing has been recently proposed as a mean to overcome spectrum sensing limitations of secondary devices. Building on this idea, we propose a protocol for a Wireless Sensor Network (WSN) to support secondary devices of an Opportunistic Spectrum Access (OSA) network. We examine the fundamental tradeoff between the statistics...
Traditional wireless sensor networks (WSNs) working in the license-free spectrum suffer from uncontrolled interference as the license-free spectrum becomes increasingly crowded. A WSN based on cognitive radios can potentially provide data transmissions with quality of service, while avoiding the high cost for accessing the licensed spectrum and uncontrolled interference in the license-free spectrum...
Performance of cognitive personal area networks is critically dependent on the accuracy of channel sensing. To ensure smooth operation of a cognitive PAN, all nodes that have data to transmit must take part in the sensing process. However, sensing affects transmission and vice versa, and a balance between sensing and data transmission must be found. One mechanism suitable for achieving this balance...
A cognitive scenario similar to BSS (basic service set) in CogMesh network is considered. Traditional MR (mesh router) is reconstructed into multi-transceiver structure, which called CMR (cognitive mesh router). CMR can allocate vacant spectrum bands for SMCs (secondary mesh client), which access the CMR with one hop. Besides, ESA algorithm is proposed according to the spectrum scenario based on the...
In this paper we evaluate the delay and sensing performance of distributed cooperative sensing in wireless sensor networks assisting cognitive secondary operation. We propose a time division multiple access protocol to exchange sensing information among neighboring sensors, that is tunable in terms of sensing cooperation range and frequency reuse distance. Our evaluation shows that short frequency...
Traditional static spectrum allocation policies have been to grant each wireless service exclusive usage of certain frequency bands, leaving several spectrum bands unlicensed for industrial, scientific and medical purposes. The rapid proliferation of low-cost wireless applications in unlicensed spectrum bands has resulted in spectrum scarcity among those bands. Since most applications in Wireless...
In recent years, we have seen tremendous growth in the applications of wireless sensor networks (WSNs) operating in unlicensed spectrum bands. However, there is evidence that existing unlicensed spectrum is becoming overcrowded. On the other hand, with recent advances in cognitive radio (CR) technology, it is possible to apply the dynamic spectrum access (DSA) model in WSNs to get access to less congested...
Cognitive radio technology necessitates accurate and timely sensing of the primary users' activity on the chosen set of channels. We assume incomplete sensing, in which the number of sensing nodes is smaller than the number of channels; the results of sensing are cooperatively combined to form a coherent channel map. As the times when spectral opportunities end are more critical for network performance,...
Cognitive radio technology necessitates accurate and timely sensing of the primary users' activity on the chosen set of channels. We assume incomplete sensing, in which the number of sensing nodes is smaller than the number of channels; the results of sensing are cooperatively combined to form a coherent channel map. As the times when spectral opportunities end are more critical for network performance,...
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