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Projecte llegit

Títol: Performance evaluation of cooperative sensing mechanisms in cognitive radio networks

Estudiants que han llegit aquest projecte:

Director/a: LEÓN ABARCA, OLGA

Departament: ENTEL

Títol: Performance evaluation of cooperative sensing mechanisms in cognitive radio networks

Data inici oferta: 02-02-2015     Data finalització oferta: 02-10-2015


Estudis d'assignació del projecte:
    GR ENG TELEMÀTICA
Tipus: Individual
 
Lloc de realització: EETAC
 
Paraules clau:
cognitive radio networks, security,byzantine attack, cooperative spectrum sensing
 
Descripció del contingut i pla d'activitats:
Radio spectrum is becoming a scarce resource because of the proliferation of wireless applications and also, due to the fact that most frequencies have been asigned in a static manner to licensed services.
Besides, recent studies show that most of these frequencies are being underutilized at any time and location, particularly in rural environments.

CRNs are networks composed of intelligent devices that can sense the medium, detect which portions of the spectrum are not being occupied and select the best channel to transmit at any moment.
Because of this, they emerge as a paradigm that allows to make a more efficient use of the spectrum by operating both in non-licensed and licensed frequency bands, provided that the CRN communications do not interfere licensed users, also denoted as primary users. In order to achieve this goal, CRNs typically implement sensing mechanisms where all members of the network cooperate by reporting their observations about the spectrum occupancy.

Cooperative spectrum sensing mechanisms in CRNs are vulnerable to many threats such as the Byzantine attack, in which one or a set of malicious nodes report fake measurements, thus leading to the CRN to wrong decisions about the occupancy of the spectrum and disrupting the performance of the network. The objectivee of this project is to analyze and commpare the most relevant prooposals that have appeared in the literature in order to counteract the Byzantine attack.


The tasks involved in this project are as follows:

1) Study of the main features of CRNs, particularly cooperative spectrum sensing mechanisms.
2) Study of the effect of the Byzantine attack on CRNs and the countermeasures appeared in the literature.
3) Implementation of the most relevant mechanisms robust to the Byzantine attacks (using Matlab, Python, ...)
4) Analysis and comparison of the different approaches.
 
Overview (resum en anglès):
C th 2015 ognitive radio networks consist of intelligent devices that perform continuo us monitoring of the RF spectrum to locate and use frequency bands that are temporarily free . That is , those bands used by licensed or primary users that are not broadcasting at this time. Through cooperative monitoring the node s in a network rep ort reports about or busy) to a node provided with different the state of the several channels (free some intelligence known as the fusion center. This node is able to combine all information received in the different and make a final decision about the stat repo rts us of the network in terms of occupancy and quality (SNR) as well as whether or not using inform ing the other nodes of the network on the frequency band previously monitored. Because they are wireless, cognitive atta cks such as the b radio networks can become vul nerable to yzantine attack by malicious entities. This attack is based on falsifying reports of network ’s nodes sent to the fusion center and can lead to a wrong decision in the fusion center, and as a result the use of a frequency band that is not f ree at that moment , or vice versa. The aim of this project is to evaluate cooperative are robust to the b yzantine attack s monitoring mechanisms that on cognitive radio networks. With this purpose, we used assess the impact of the b Matlab software to simulate various scenario yzantine attack s an d in cognitive radio networks’ operation in terms of probability of detection and false alarm probability, that is, the probability that final decision of fusion center is correct or not, under the presence or abse nce of primary user or not, respectively. In addition, we have compared the simulation results with those obtained by analytical expressions. Also, since there is the possibility that the secondary compromised by an attacker in order to falsif y their reports nodes become , various methods which objective is to identify and exclude the suspected nodes that can be falsifying its reports in order to prevent the wrong functioning of the network have been evaluated.

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