Об особенностях мониторинга занятости частотных ресурсов каналов связи при передаче информации когнитивными системами беспроводной связи

Проводится анализ методов детектирования применяемых в стандарте когнитивного радио путем имитационного моделирования в среде MATLA

An analysis on decentralized adaptive MAC protocols for Cognitive Radio networks

The scarcity of bandwidth in the radio spectrum has become more vital since the demand for more and more wireless applications has increased. Most of the spectrum bands have been allocated although many studies have shown that these bands are significantly underutilized most of the time. The problem of unavailability of spectrum and inefficiency in its utilization has been smartly addressed by the Cognitive Radio (CR) Technology which is an opportunistic network that senses the environment, observes the network changes, and then using knowledge gained from the prior interaction with the network, makes intelligent decisions by dynamically adapting their transmission characteristics. In this paper some of the decentralized adaptive MAC protocols for CR networks have been critically analyzed and a novel adaptive MAC protocol for CR networks, DNG-MAC which is decentralized and non-global in nature, has been proposed. The results show the DNG-MAC out performs other CR MAC protocols in terms of time and energy efficiency

Оцінка ефективності використання спектру при впровадженні технології ІЕЕЕ 802.22

Розглянуто загальну методику оцінки використання спектру системами радіозв’язку. На її основі запропоновано методику розрахунку технічної ефективності впровадження технології безпровідних регіональних мереж IEEE 802.22 з урахуванням первинної мережі телебачення. Проведено оцінку ефективності використання спектру цією технологією для заданого регіону та доведено доцільність побудови подібних мережThe general method of estimation spectrum use of radio communication systems is considered. The calculation of the technical efficiency in implementation of wireless technology of regional networks of IEEE 802.22 over primary television network is proposed on basis of this method. The estimation of spectrum use efficiency of this technology in specified region is performed and the feasibility of development such networks is prove

Dynamic channel selection for multi-user video streaming over cognitive radio networks

Due to the dynamic nature of cognitive radio networks, multi-user video streaming (with various video traffic characteristics and QoS requirements) requires efficient dynamic channel selection schemes to exploit available spectrum resources. To do this, a wireless user needs to effectively model the dynamic wireless environment and estimate the delay of video packet transmission when selecting a specific frequency channel. In this paper, we apply the priority virtual queue model for these wireless users to adapt their channel selection and maximize video qualities. The simulation results show that the proposed channel selection solution based on priority scheduling outperforms the conventional dynamic channel selection scheme by 2 dB (PSNR). Index Terms — Video streaming, cognitive radio networks, priority queuing analysis