Secrecy performance of cognitive cooperative industrial radio networks

Abstract

Although cognitive radio networks (CRNs) were originally intended as a powerful solution to enhance spectrum utilization, it can also be used to improve reliability by avoiding interference in the 2.4 or 5 GHz band. Using multiple relay nodes in CRNs, the outage probability, i.e., the probability that the endto-end signal-to-noise ratio drops below a predefined threshold, can be reduced significantly. T his i mplies t hat t he probability that a message is not delivered within a specific t ime frame, can be kept below a required threshold, even when there are constraints on energy efficiency in terms of peak transmit power. This is particularly useful for industrial networks with realtime constraints. However, using CRNs may also reveal secret information to eavesdroppers (EAVs). Therefore, guaranteeing secure and reliable communications in CRNs is still a challenging problem. To this end, the secrecy performance of a proactive decode-and-forward relaying scheme in a cognitive cooperative radio network is investigated. More specifically, analytical as well as approximate expressions for the secrecy outage probability and probability of non-zero secrecy capacity are derived to evaluate the system performance. Numerical results show that the approximation tightly match the analytical results and simulations, and thus it can be used to provide a fast evaluation of the security and reliability of communications using a considered assignment of relay nodes in a cognitive cooperative radio network (CCRN). Consequently, our results enable to secure the communication, and increasing the reliability, availability, robustness, and maintainability of wireless industrial network, subject to various constraints from the CRN.

Secrecy Performance of Cooperative Cognitive Radio Networks Under Joint Secrecy Outage and Primary User Interference Constraints

“…where C E2E and C E are defined in (11) and (12), respectively. The system fail when the information is not secure and/or reliable.…”

“…In here, to calculate the integrals in O 1 and O 2 , we use the help of a lemma which has been proved in the our previous study [12,Lemma 1]. The lemma is presented as follows: Lemma 1: Assuming A, B, C, D, and δ are positive constants, we have…”

“…This becomes even more serious in CRN as the spectrum band is shared by a secondary network and even more so when cooperative communications is introduced. This problem was addressed in [12] where the secrecy outage performance of cooperative cognitive radio networks (CCRN) was derived under interference constraints from the PU. Secrecy outage is achieved when an eavesdropper (EAV) cannot decode the targeted signal, but communications between nodes in the secondary network is still possible.…”

“…Secrecy outage is achieved when an eavesdropper (EAV) cannot decode the targeted signal, but communications between nodes in the secondary network is still possible. The solution in [12] indicates that it requires careful power allocation policies to achieve secrecy outage towards the EAV, while also maintaining the interference constraints set by the PU.…”

“…As an extension of the work in [12], we study here power allocation policies capable of fulling the secrecy outage constraint as well as the PU interference constraints of the CRN. Considering the above constraints and the channel conditions, the major contributions in this paper are summarised as follows:…”