naa a22 4500 510798136 CHVBK 20180411083344.0 cr unu---uuuuu 180411e20131001xx s 000 0 eng 10.1007/s11277-013-1147-3 doi (NATIONALLICENCE)springer-10.1007/s11277-013-1147-3 Performance Evaluation of Secondary Users Operating on a Heterogeneous Spectrum Environment [Elektronische Daten] [Mohamed Kalil, Hassan Al-Mahdi, Andreas Mitschele-Thiel] Radio spectrum is a limited natural resource and with the increasing number of wireless devices, an efficient spectrum management concept to make a better utilization of this resource is essential. Opportunistic spectrum access (OSA) concept is a solution to increase the spectrum capacity and thus reducing the data collision for wireless ad hoc networks. Cognitive radio (CR) technology is developed to realize OSA. Based on CR, the secondary users access opportunistically the spectrum owned by primary users. However, the consequence appearance of primary users affects greatly the performance of secondary users within OSA. Thus, a new spectrum management scheme is a must to reduce such effect. In this paper, a new spectrum management scheme over a heterogeneous spectrum environment is proposed. The proposed scheme is based on using channels from both licensed and unlicensed bands as spectrum environment for ad hoc networks. An analytical model based on Markov chains is developed to evaluate the proposed scheme. Springer Science+Business Media New York, 2013 Opportunistic spectrum access nationallicence Cognitive radio nationallicence Spectrum management nationallicence Markov chains nationallicence Kalil Mohamed Integrated Communications Systems Group, Ilmenau University of Technology, Ilmenau, Germany aut Al-Mahdi Hassan Faculty of Computers and Informations, Suez Canal University, Ismailia, Egypt aut Mitschele-Thiel Andreas Integrated Communications Systems Group, Ilmenau University of Technology, Ilmenau, Germany aut Wireless Personal Communications Springer US; http://www.springer-ny.com 72/4(2013-10-01), 2251-2262 0929-6212 72:4<2251 2013 72 11277 https://doi.org/10.1007/s11277-013-1147-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11277-013-1147-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kalil Mohamed Integrated Communications Systems Group, Ilmenau University of Technology, Ilmenau, Germany aut NATIONALLICENCE 700 1- Al-Mahdi Hassan Faculty of Computers and Informations, Suez Canal University, Ismailia, Egypt aut NATIONALLICENCE 700 1- Mitschele-Thiel Andreas Integrated Communications Systems Group, Ilmenau University of Technology, Ilmenau, Germany aut NATIONALLICENCE 773 0- Wireless Personal Communications Springer US; http://www.springer-ny.com 72/4(2013-10-01), 2251-2262 0929-6212 72:4<2251 2013 72 11277 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer