79 research outputs found
Block Outlier Methods for Malicious User Detection in Cooperative Spectrum Sensing
Block outlier detection methods, based on Tietjen-Moore (TM) and Shapiro-Wilk
(SW) tests, are proposed to detect and suppress spectrum sensing data
falsification (SSDF) attacks by malicious users in cooperative spectrum
sensing. First, we consider basic and statistical SSDF attacks, where the
malicious users attack independently. Then we propose a new SSDF attack, which
involves cooperation among malicious users by masking. In practice, the number
of malicious users is unknown. Thus, it is necessary to estimate the number of
malicious users, which is found using clustering and largest gap method.
However, we show using Monte Carlo simulations that, these methods fail to
estimate the exact number of malicious users when they cooperate. To overcome
this, we propose a modified largest gap method.Comment: Accepted in Proceedings of 79th IEEE Vehicular Technology
Conference-Spring (VTC-Spring), May 2014, Seoul, South Kore
Fully Distributed Cooperative Spectrum Sensing for Cognitive Radio Networks
Cognitive radio networks (CRN) sense spectrum occupancy and manage themselves to operate in unused bands without disturbing licensed users. The detection capability of a radio system can be enhanced if the sensing process is performed jointly by a group of nodes so that the effects of wireless fading and shadowing can be minimized. However, taking a collaborative approach poses new security threats to the system as nodes can report false sensing data to force a wrong decision. Providing security to the sensing process is also complex, as it usually involves introducing limitations to the CRN applications. The most common limitation is the need for a static trusted node that is able to authenticate and merge the reports of all CRN nodes. This paper overcomes this limitation by presenting a protocol that is suitable for fully distributed scenarios, where there is no static trusted node
Equity-Based free channels assignment for secondary users in a cognitive radio network
The present paper addresses the equity issue among the secondary users in a cognitive radio network. After using a multi scheduler algorithm and a fairness metric namely Jainâs Equity Index; we enhance the equity between the secondary usersâ transfer rates by 0.64 in average, relative to a previous work
A Secure Cooperative Sensing Protocol for Cognitive Radio Networks
Cognitive radio networks sense spectrum occupancy
and manage themselves to operate in unused bands without disturbing licensed users. Spectrum sensing is more accurate if jointly performed by several reliable nodes. Even though cooperative sensing is an active area of research, the secure
authentication of local sensing reports remains unsolved, thus empowering false results. This paper presents a distributed protocol based on digital signatures and hash functions, and an
analysis of its security features. The system allows determining a final sensing decision from multiple sources in a quick and secure way.Las redes de radio cognitiva detectora de espectro se las arreglan para operar en las nuevas bandas sin molestar a los usuarios con licencia. La detecciĂłn de espectro es mĂĄs precisa
si el conjunto estĂĄ realizado por varios nodos fiables. Aunque la detecciĂłn cooperativa es un ĂĄrea activa de investigaciĂłn, la autenticaciĂłn segura de informes locales de detecciĂłn no ha sido resuelta, por lo tanto se pueden dar resultados falsos. Este trabajo presenta un protocolo distribuido basado en firmas digitales y en funciones hash, y un anĂĄlisis de sus caracterĂsticas de seguridad. El sistema permite determinar una decisiĂłn final de detecciĂłn de mĂșltiples fuentes de una manera rĂĄpida y segura.Les xarxes de rĂ dio cognitiva detectora d'espectre se les arreglen per operar en les noves bandes sense destorbar els usuaris amb llicĂšncia. La detecciĂł d'espectre Ă©s mĂ©s precisa
si el conjunt estĂ realitzat per diversos nodes fiables. Encara que la detecciĂł cooperativa Ă©s una Ă rea activa d'investigaciĂł, l'autenticaciĂł segura d'informes locals de detecciĂł no ha estat resolta, per tant es poden donar resultats falsos. Aquest treball presenta un protocol distribuĂŻt basat en signatures digitals i en funcions hash, i una anĂ lisi de les seves caracterĂstiques de seguretat. El sistema permet determinar una decisiĂł final de detecciĂł de mĂșltiples fonts d'una manera rĂ pida i segura
Cognitive node selection and assignment algorithms for weighted cooperative sensing in radar systems
Trust-based Throughput in Cognitive Radio Networks
Cognitive Radio Networks (CRNs) deal with opportunistic spectrum access in order to fully utilize the scarce of spectrum resources, with the development of cognitive radio technologies to greater utilization of the spectrum. Nowa- days Cognitive Radio (CR) is a promising concept for improving the utilization of limited radio spectrum resources for future wireless communications and mobile computing. In this paper, we propose two approaches. At first we propose a trust aware model to authenticate the secondary users (SUs) in CRNs which provides a reliable technique to establish trust for CRNs. Secondly, we propose trust throughput mechanism to measure throughput in CRNs
Cognitive Radio Networks: Realistic or Not?
A large volume of research has been conducted in the cognitive radio (CR)
area the last decade. However, the deployment of a commercial CR network is yet
to emerge. A large portion of the existing literature does not build on real
world scenarios, hence, neglecting various important interactions of the
research with commercial telecommunication networks. For instance, a lot of
attention has been paid to spectrum sensing as the front line functionality
that needs to be completed in an efficient and accurate manner to enable an
opportunistic CR network architecture. This is necessary to detect the
existence of spectrum holes without which no other procedure can be fulfilled.
However, simply sensing (cooperatively or not) the energy received from a
primary transmitter cannot enable correct dynamic spectrum access. For example,
the low strength of a primary transmitter's signal does not assure that there
will be no interference to a nearby primary receiver. In addition, the presence
of a primary transmitter's signal does not mean that CR network users cannot
access the spectrum since there might not be any primary receiver in the
vicinity. Despite the existing elegant and clever solutions to the DSA problem
no robust, implementable scheme has emerged. In this paper, we challenge the
basic premises of the proposed schemes. We further argue that addressing the
technical challenges we face in deploying robust CR networks can only be
achieved if we radically change the way we design their basic functionalities.
In support of our argument, we present a set of real-world scenarios, inspired
by realistic settings in commercial telecommunications networks, focusing on
spectrum sensing as a basic and critical functionality in the deployment of
CRs. We use these scenarios to show why existing DSA paradigms are not amenable
to realistic deployment in complex wireless environments.Comment: Work in progres
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