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As a critical technique to support the multimedia services - the major traffic in cooperative cognitive radio networks (CRNs), the statistical quality-of-service (QoS) technique has been proved to be effective in statistically guaranteeing delay-bounded video transmissions over the time- varying wireless channels. On the other hand, in modern cooperative CRNs, the full-duplex spectrum sensing (FD-SS)...
Cognitive radio (CR) is a key enabler of wireless in industrial applications especially for those with strict quality-of-service (QoS) requirements. The cornerstone of CR is spectrum occupancy prediction that enables agile and proactive spectrum access and efficient utilization of spectral resources. Hidden Markov Models (HMM) provide powerful and flexible tools for statistical spectrum prediction...
With the growing demand for wireless applications, there is an incalculable rise in bandwidth consumption that in turn leads to the spectrum scarcity. The conflict between spectrum underutilization and spectrum scarcity is solved by a well-known technology called Cognitive Radio (CR). The main aim of CR is to exploit unutilized spectrum of licensed users/Primary Users (PUs) and enable opportunistic...
Scarcity of the radio frequency spectrum available for use by the vast number of wireless devices is already a challenge faced by ubiquitous communication networks, including the Internet of Things. The Cognitive Radio (CR) technology provides promising solutions to address part of such challenges. CR is based on allowing the so-called holes, the spectrums that remain unoccupied by their licensed...
Admitting the appropriate network architecture with an efficient working model is an essential task to enable exploiting Cognitive Radio (CR) technology in the wireless sensing applications. Given the different QoS requirements essential for a variety of traffic types in different work scenarios, this paper reviews the related challenges facing the Cognitive Radio Sensor Network (CRSN) implementation...
Wireless Sensor Network (WSN) is comprised of small and low-cost sensors deployed in a particular region in order to monitor a phenomena. In this paper, we have addressed some problems, which have significant effects on the performance of WSNs while computing the path from source to the base station. Although in the literature, many MAC protocols for WSNs have been proposed based on QoS to save the...
Cooperative relay enables general multi-hop cognitive radio networks (CRN) over cognitive radios (CR) and nodes of primary system (PS). However, successful CR networking such as routing relies on the knowledge of radio resource availability associated with location, which is a challenge of traditional spectrum sensing. We introduce the concept of spectrum map encompassing spectrum and location information...
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...
Cognitive Radio (CR) seems to be a promising solution to the radio spectrum congestion problem by opportunistic uses of the spectral holes to achieve efficient use of the frequency resource by allowing the coexistence of licensed (primary) and unlicensed (secondary) users in the same bandwidth. According to the cooperative wireless communication (CWC) concept the active nodes may increase their effective...
We propose the queue-aware spectrum sensing schemes for interference-constrained opportunistic transmissions of secondary users (SUs) in cognitive radio networks. Specifically, we employ the energy detection for SUs to sense the spectrum-usage status of the primary users (PUs). Unlike the traditional energy detector using a fixed energy threshold to decide the presence of the PUs' signals, we dynamically...
Spectrum scarcity and the inefficiency in its usage have necessitates the use of Cognitive Radio (CR) technology to exploit the existing wireless spectrum opportunistically. Spectrum sensing is a critical component of CR as it is a fundamental requirement that a cognitive user (CU) continuously senses the channel before accessing it to avoid causing interference to the primary user (PU) and other...
Cognitive radio (CR) is an effective technology for flexible utility of radio spectrum and has received increasing attention so far. To ensure reliable spectrum sensing, quiet periods (QPs) are allocated during which all secondary users cease transmission and perform spectrum sensing. Such that, regular transmission will be interrupted periodically and the system quality of service (QoS) could be...
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