Cognitive radio technology for flexible spectrum sharing

Recent study by FCC Spectrum-Policy Task Force (SPTF) found that while the available spectrum becomes increasingly scarce, the assigned spectrum is significantly underutilized. Cognitive radio (CR) technology refers to a new type of radio hat uses real-time interaction with its environment to determine transmitter parameters such as frequency, power, and modulation. This paper presents a preliminary survey of CR with the goal of quantifying spectral occupancy and thereby gaining some insight into its feasibility. Two case studies were investigated: ultra-wide bandwidth technology as a transmission technique suitable for implementing a cognitive radio system was discussed, and a comparable measurement of TV spectrum band in an urban environment is also presented

Improved Spectrum Mobility using Virtual Reservation in Collaborative Cognitive Radio Networks

Cognitive radio technology would enable a set of secondary users (SU) to opportunistically use the spectrum licensed to a primary user (PU). On the appearance of this PU on a specific frequency band, any SU occupying this band should free it for PUs. Typically, SUs may collaborate to reduce the impact of cognitive users on the primary network and to improve the performance of the SUs. In this paper, we propose and analyze the performance of virtual reservation in collaborative cognitive networks. Virtual reservation is a novel link maintenance strategy that aims to maximize the throughput of the cognitive network through full spectrum utilization. Our performance evaluation shows significant improvements not only in the SUs blocking and forced termination probabilities but also in the throughput of cognitive users.Comment: 7 pages, 10 figures, IEEE ISCC 201

CRB-RPL: A Receiver-based Routing Protocol for Communications in Cognitive Radio Enabled Smart Grid

As a tool of overcoming radio spectrum shortages in wireless communications, cognitive radio technology plays a vital role in future smart grid applications, particularly in Advanced Metering Infrastructure (AMI) networks with Quality of Service (QoS) requirements. This paper focuses on the investigation of the receiver-based routing protocol for enhancing QoS in cognitive radio-enabled AMI networks, due to their potentials of enhancing reliability and routing efficiency. In accordance with practical requirements of smart grid applications, a new routing protocol with two purposes is proposed: one is to address the realtime requirement while another protocol focuses on how to meet energy efficiency requirements. As a special feature of cognitive radio technology, the protocol have the mechanism of protecting primary (licensed) users whilst meeting the utility requirements of secondary (cognitive radio) users. System-level evaluation shows that the proposed routing protocol can achieve better performances compared with existing routing protocols for cognitive radio-enabled AMI networks

Primary User Emulation Attacks: A Detection Technique Based on Kalman Filter

Cognitive radio technology addresses the problem of spectrum scarcity by allowing secondary users to use the vacant spectrum bands without causing interference to the primary users. However, several attacks could disturb the normal functioning of the cognitive radio network. Primary user emulation attacks are one of the most severe attacks in which a malicious user emulates the primary user signal characteristics to either prevent other legitimate secondary users from accessing the idle channels or causing harmful interference to the primary users. There are several proposed approaches to detect the primary user emulation attackers. However, most of these techniques assume that the primary user location is fixed, which does not make them valid when the primary user is mobile. In this paper, we propose a new approach based on the Kalman filter framework for detecting the primary user emulation attacks with a non-stationary primary user. Several experiments have been conducted and the advantages of the proposed approach are demonstrated through the simulation results.Comment: 14 pages, 9 figure

Cognitive radio technology in the UHF band

Las empresas de comunicaciones celulares móviles en Colombia requieren mayor recurso espectral para ampliar su portafolio de servicios; sin embargo, no hay frecuencias adicionales para tal fin, no obstante es conocido que existe infrautilización de muchas bandas licenciadas. Por esta razón nuevas tecnologías de radio son estudiadas para su implementación en búsqueda de solucionar este problema, ellas son: Radio Definida por Software (RDS ) [1], Radio Cognición (RC) [2] y Acceso Dinámico al Espectro (ADE) [3]. Estas estrategias proponen movilidad en todo el espectro de las comunicaciones de radio para suplir necesidades y lograr mayor eficiencia en la administración de dicho recurso. Desde esta perspectiva se presenta un estudio de caso para examinar los requisitos que se deben cumplir para la implementación de una red de radio cognitiva en Bogotá, para lo cual se evaluó la posibilidad de migración de las comunicaciones celulares desde sus bandas asignadas a las bandas de televisión UHF, y la coexistencia sin interferencias entre estos 2 servicios. El estudio arrojó viabilidad en dicha migración; sin embargo, la implementación de radio cognitiva compromete voluntades de los operadores y del Ministerio de Tecnologías de la Información y las Comunicaciones de Colombia, y demanda disponibilidad de hardware, software y plataformas de radio flexibles.Mobile cellular communication companies in Colombia require more spectrum resources to expand their portfolio of services. However, additional frequency bands for that particular purpose are scarce, yet it is well known that there are many underutilized licensed bands. Therefore new radio technologies are being studied in order to solve this problem, e.g. Software Defi ned Radio SDR [1] Cognitive Radio CR [2] and Dynamic Spectrum Access DSA [3]. These strategies recommend mobility across the radio spectrum to meet various needs and achieve greater effi ciency when managing such a scarce resource. In this context, a case study is presented in an attempt to examine the requirements that must be met for the implementation of cognitive radio networks in Bogota. The case study includes evaluation for the possibility of migration from cellular communications to cognitive radio since the bands assigned to UltraHigh Frequency UHF television offer possible free-of-interference coexistence between the two services (i.e. Cellular and TV). The study shows feasibility to migration; however, the implementations of cognitive radio need availability of hardware, software and flexible radio platforms