The Experts below are selected from a list of 84 Experts worldwide ranked by ideXlab platform
Hiroshi Harada - One of the best experts on this subject based on the ideXlab platform.
-
efficiency of Dynamic Frequency Selection based coexistence mechanisms for tv white space enabled cognitive wireless access points
IEEE Wireless Communications, 2012Co-Authors: Gabriel Porto Villardi, Chinsea Sum, Yohannes D Alemseged, Hiroshi HaradaAbstract:We investigate the efficiency of Dynamic Frequency Selection (DFS) in mitigating interference among neighboring low-power cognitive wireless portable networks operating in the TV white space. We derive an interference model to predict the range and level of interference generated in the TV bands by portable low-height antenna cognitive wireless access points in suburban and urban areas. Based on the aforementioned model, we provide an analysis of the spectral availability for either the scenarios where DFS coexistence is employed or not. The steps of our analysis are introduced in a tutorial fashion, and a coexistence case study of TVWS enabled low-power cognitive wireless portable APs in Japan is presented. Our analysis demonstrates the intrinsic relationship SA holds with the TVWS channel set as well as statistical information (e.g., household density of wards and cities, Internet penetration, and white space radio AP market penetration).
-
autonomous Dynamic Frequency Selection for wlans operating in the tv white space
International Conference on Communications, 2011Co-Authors: Chunyi Song, Chinsea Sum, Junyi Wang, Tunce Aykas, Hiroshi HaradaAbstract:This paper describes the challenges of Frequency channel Selection for WLANs operating in the TV White Space (TVWS) and proposes a Dynamic Frequency Selection (DFS) technique as a solution. Based on the statistics gained from past usage experience of channels, of the TVWS channels' vacancies and channel occupation by the adjacent WLANs, each WLAN evaluates and prioritize the channels independently using a priority function. Then by selecting the channel of the highest priority among vacant channels, each WLAN can quickly find a channel in the low interference regime and whose vacancy is adaptive to its traffic load distribution as well. Performance of the proposed DFS is evaluated through simulation using QualNet, based on TVWS channels with realistic feature and by setting the weight factors of different metrics in the priority function to different values. The evaluation results show that compared to conventional DFS, the proposed DFS avoids adjacent APs selecting the same channel and reduces channel switch rate, and is more adaptive to diverse environments. As a consequence, it maximally reduces total time consumption of channel switch by 40% than random Selection.
Chinsea Sum - One of the best experts on this subject based on the ideXlab platform.
-
efficiency of Dynamic Frequency Selection based coexistence mechanisms for tv white space enabled cognitive wireless access points
IEEE Wireless Communications, 2012Co-Authors: Gabriel Porto Villardi, Chinsea Sum, Yohannes D Alemseged, Hiroshi HaradaAbstract:We investigate the efficiency of Dynamic Frequency Selection (DFS) in mitigating interference among neighboring low-power cognitive wireless portable networks operating in the TV white space. We derive an interference model to predict the range and level of interference generated in the TV bands by portable low-height antenna cognitive wireless access points in suburban and urban areas. Based on the aforementioned model, we provide an analysis of the spectral availability for either the scenarios where DFS coexistence is employed or not. The steps of our analysis are introduced in a tutorial fashion, and a coexistence case study of TVWS enabled low-power cognitive wireless portable APs in Japan is presented. Our analysis demonstrates the intrinsic relationship SA holds with the TVWS channel set as well as statistical information (e.g., household density of wards and cities, Internet penetration, and white space radio AP market penetration).
-
autonomous Dynamic Frequency Selection for wlans operating in the tv white space
International Conference on Communications, 2011Co-Authors: Chunyi Song, Chinsea Sum, Junyi Wang, Tunce Aykas, Hiroshi HaradaAbstract:This paper describes the challenges of Frequency channel Selection for WLANs operating in the TV White Space (TVWS) and proposes a Dynamic Frequency Selection (DFS) technique as a solution. Based on the statistics gained from past usage experience of channels, of the TVWS channels' vacancies and channel occupation by the adjacent WLANs, each WLAN evaluates and prioritize the channels independently using a priority function. Then by selecting the channel of the highest priority among vacant channels, each WLAN can quickly find a channel in the low interference regime and whose vacancy is adaptive to its traffic load distribution as well. Performance of the proposed DFS is evaluated through simulation using QualNet, based on TVWS channels with realistic feature and by setting the weight factors of different metrics in the priority function to different values. The evaluation results show that compared to conventional DFS, the proposed DFS avoids adjacent APs selecting the same channel and reduces channel switch rate, and is more adaptive to diverse environments. As a consequence, it maximally reduces total time consumption of channel switch by 40% than random Selection.
Gabriel Porto Villardi - One of the best experts on this subject based on the ideXlab platform.
-
efficiency of Dynamic Frequency Selection based coexistence mechanisms for tv white space enabled cognitive wireless access points
IEEE Wireless Communications, 2012Co-Authors: Gabriel Porto Villardi, Chinsea Sum, Yohannes D Alemseged, Hiroshi HaradaAbstract:We investigate the efficiency of Dynamic Frequency Selection (DFS) in mitigating interference among neighboring low-power cognitive wireless portable networks operating in the TV white space. We derive an interference model to predict the range and level of interference generated in the TV bands by portable low-height antenna cognitive wireless access points in suburban and urban areas. Based on the aforementioned model, we provide an analysis of the spectral availability for either the scenarios where DFS coexistence is employed or not. The steps of our analysis are introduced in a tutorial fashion, and a coexistence case study of TVWS enabled low-power cognitive wireless portable APs in Japan is presented. Our analysis demonstrates the intrinsic relationship SA holds with the TVWS channel set as well as statistical information (e.g., household density of wards and cities, Internet penetration, and white space radio AP market penetration).
Luiz A Dasilva - One of the best experts on this subject based on the ideXlab platform.
-
on opportunistic spectrum access in radar bands lessons learned from measurement of weather radar signals
IEEE Wireless Communications, 2016Co-Authors: Zaheer Khan, Janne Lehtomaki, Risto Vuohtoniemi, Ekram Hossain, Luiz A DasilvaAbstract:The need for extra spectrum and the fact that a large amount of spectrum below 6 GHz is allocated to radar systems has motivated regulatory bodies and researchers to investigate the feasibility of Dynamic spectrum access in radar bands. To design efficient wireless communication schemes that coexist with radar systems, it is essential that the wireless community thoroughly understand the operations of these systems in different bands. This article studies incumbent operations and usage patterns in the 5 GHz band, where weather radar systems dominate, Dynamic Frequency Selection is employed as a sharing mechanism, and recent works have explored the possibility to temporally share the spectrum with such radar systems. We present a measurement-based study of spectrum usage by a weather radar in Finland. Our measurement results show that the weather radar's scan patterns are quasi-periodic, and that use of sensing may not reliably detect radar signals due to its quasi-periodic scanning patterns and different vertical scanning angles. Finally, we present a framework for a database-assisted temporal sharing coexistence mechanism that takes into account the real occupancy behavior of the radar.
Yohannes D Alemseged - One of the best experts on this subject based on the ideXlab platform.
-
efficiency of Dynamic Frequency Selection based coexistence mechanisms for tv white space enabled cognitive wireless access points
IEEE Wireless Communications, 2012Co-Authors: Gabriel Porto Villardi, Chinsea Sum, Yohannes D Alemseged, Hiroshi HaradaAbstract:We investigate the efficiency of Dynamic Frequency Selection (DFS) in mitigating interference among neighboring low-power cognitive wireless portable networks operating in the TV white space. We derive an interference model to predict the range and level of interference generated in the TV bands by portable low-height antenna cognitive wireless access points in suburban and urban areas. Based on the aforementioned model, we provide an analysis of the spectral availability for either the scenarios where DFS coexistence is employed or not. The steps of our analysis are introduced in a tutorial fashion, and a coexistence case study of TVWS enabled low-power cognitive wireless portable APs in Japan is presented. Our analysis demonstrates the intrinsic relationship SA holds with the TVWS channel set as well as statistical information (e.g., household density of wards and cities, Internet penetration, and white space radio AP market penetration).
