Spectrum Sharing Secondary Users in Presence of Multiple Adversaries

Abstract

Cognitive radio technology brings a lot of interesting features which affect the transmission and reception properties of modern communication devices. Dynamic spectrum sensing, channel hopping, allocation and strategically nullifying adversarial attacks are among the few. In the presence of primary users (PUs), we inspect the secondary user (SU) pair behavior in decentralized, ad hoc cognitive radio networks, before and after adversarial attacks. We have taken into consideration the power radius of each SU pair to calculate the payoffs which decide if they should participate in a coalition or not. We propose algorithms for coalition formation for the SU pairs and the adversaries. We also propose two attack strategies for the adversaries: smart or naive. Overall, we propose a game-theoretic framework to study the multi-SU-pair multi-adversary scenario. We investigate the effect of adversarial attacks on the proposed framework. We show that the decrease in the average utilities of the SU pairs after attack varies from 66% to 75% with adversary count increasing by 14.2%. We study how the channels are allocated if there is an attack and how the payoffs of those SU pairs vary with increasing or decreasing number of channels. We also show that the payoffs decrease by 14.66%, if adversaries adopt a smart strategy instead of a naive one.