In this paper, three different relay and jammers selection schemes are presented to improve the physical layer security of two-way cooperative networks in the presence of multiple cooperating and non-cooperating eavesdroppers. The presented selection schemes are; optimal selection scheme without jamming, optimal selection scheme with conventional jamming, and optimal selection scheme with controlled jamming. The proposed schemes select three intermediate nodes during two communication phases. In the first phase, a friendly jammer is selected to create intentional interference at the eavesdroppers' nodes. In the second phase, two relay nodes are selected; one node is selected to operate as a conventional relay and assists the sources to deliver their data to the corresponding destinations via a Decode-and-Forward (DF) strategy. While the other node behaves as a jammer node in order to confuse the eavesdroppers in this phase. The proposed schemes are analyzed in terms of ergodic secrecy rate and secrecy outage probability. The obtained results show that the jamming schemes outperform the non-jamming schemes in the eavesdroppers' environment. Moreover, cooperating eavesdroppers' further degrade system's secrecy performance than the non-cooperating ones. Finally, a comparison between relay and jammers selection schemes in both one-way and two-way cooperative networks is given in terms of both ergodic secrecy rate and secrecy outage probability metrics.
In this paper, three different relay and jammers selection schemes are presented to improve the physical layer security of two-way cooperative networks in the presence of multiple cooperating and non-cooperating eavesdroppers. The presented selection schemes are; optimal selection scheme without jamming, optimal selection scheme with conventional jamming, and optimal selection scheme with controlled jamming. The proposed schemes select three intermediate nodes during two communication phases. In the first phase, a friendly jammer is selected to create intentional interference at the eavesdroppers' nodes. In the second phase, two relay nodes are selected; one node is selected to operate as a conventional relay and assists the sources to deliver their data to the corresponding destinations via a Decode-and-Forward (DF) strategy. While the other node behaves as a jammer node in order to confuse the eavesdroppers in this phase. The proposed schemes are analyzed in terms of ergodic secrecy rate and secrecy outage probability. The obtained results show that the jamming schemes outperform the non-jamming schemes in the eavesdroppers' environment. Moreover, cooperating eavesdroppers' further degrade system's secrecy performance than the non-cooperating ones. Finally, a comparison between relay and jammers selection schemes in both one-way and two-way cooperative networks is given in terms of both ergodic secrecy rate and secrecy outage probability metrics.
In this paper, we investigate joint relay and jammer selection in two-way cooperative networks, consisting of two sources, a number of intermediate nodes, and one eavesdropper, with the constraints of physical layer security. Specifically, the proposed algorithms select two or three intermediate nodes to enhance security against the malicious eavesdropper. The first selected node operates in the conventional relay mode and assists the sources to deliver their data to the corresponding destinations using an amplify-and-forward protocol. The second and third nodes are used in different communication phases as jammers in order to create intentional interference upon the eavesdropper node. Firstly, we find that in a topology where the intermediate nodes are randomly and sparsely distributed, the proposed schemes with cooperative jamming outperform the conventional non-jamming schemes within a certain transmitted power regime. We also find that, in the scenario in which the intermediate nodes gather as a close cluster, the jamming schemes may be less effective than their non-jamming counterparts. Therefore, we introduce a hybrid scheme to switch between jamming and non-jamming modes. Simulation results validate our theoretical analysis and show that the hybrid switching scheme further improves the secrecy rate.
In this paper, we investigate joint relay and jammer selection in two-way cooperative networks, consisting of two sources, a number of intermediate nodes, and one eavesdropper, with the constraints of physical-layer security. Specifically, the proposed algorithms select two or three intermediate nodes to enhance security against the malicious eavesdropper. The first selected node operates in the conventional relay mode and assists the sources to deliver their data to the corresponding destinations using an amplify-and-forward protocol. The second and third nodes are used in different communication phases as jammers in order to create intentional interference upon the malicious eavesdropper. First, we find that in a topology where the intermediate nodes are randomly and sparsely distributed, the proposed schemes with cooperative jamming outperform the conventional nonjamming schemes within a certain transmitted power regime. We also find that, in the scenario where the intermediate nodes gather as a close cluster, the jamming schemes may be less effective than their nonjamming counterparts. Therefore, we introduce a hybrid scheme to switch between jamming and nonjamming modes. Simulation results validate our theoretical analysis and show that the hybrid switching scheme further improves the secrecy rate.
In this paper, we investigate joint relay and jammer selection in two-way cooperative networks, consisting of two sources, a number of intermediate nodes, and one eavesdropper, with secrecy constraints. Specifically, the proposed algorithms select two or three intermediate nodes to enhance security against the malicious eavesdropper. The first selected node operates in the conventional relay mode and assists the sources to deliver their data to the corresponding destinations via the amplify-and-forward protocol. The second and third nodes are used in different communication phases as jammers in order to create intentional interference upon the eavesdropper node. Firstly, we find that in a topology where the relay and jamming nodes are randomly and sparsely distributed, the proposed schemes with cooperative jamming outperforms the conventional non-jamming schemes within a certain transmitted power regime. We also find that, in the scenario in which the intermediate nodes gather as a close cluster, the jamming schemes may be less effective than their non-jamming counterparts. Therefore, we introduce a hybrid scheme to switch between jamming and non-jamming modes. Simulation results validate our theoretical analysis that the hybrid switching scheme further improves the secrecy rate.
In this paper, we investigate joint relay and jammer selection in two-way cooperative networks, consisting of two sources, one eavesdropper, and a number of intermediate nodes, with secrecy constraints. Specifically, the proposed schemes select two or three intermediate nodes to enhance security against the malicious eavesdropper. The first selected node operates in the conventional relay mode and assists the two sources to exchange data with each other in the amplify-and-forward protocol. The second and third selected nodes are used in different communication phases as jammers in order to create intentional interference upon the eavesdropper. We find that in a scenario where the relay and jamming nodes are randomly and sparsely distributed, the proposed schemes with cooperative jamming outperform the conventional non-jamming schemes within a certain transmitted power range. We also find that, in a scenario where the intermediate nodes gather as a close cluster, the cooperative jamming schemes may be less effective than their non-jamming counterparts. Therefore, we introduce a hybrid scheme to switch between jamming and non-jamming modes. Simulation results validate our theoretical analysis that the hybrid switching scheme further improves the secrecy rate.
Relay selection for physical layer security is investigated in Decode-and-forward (DF) two-way relay networks, consisting of a group of intermediate nodes, two sources, and one eavesdropper. Three intermediate nodes are selected in the two transmission phases. One intermediate node is selected to perform the relaying operation, and the other two are selected to transmit the jamming to deteriorate the eavesdropping channels. It is found that the cooperative jamming scheme outperforms the conventional non-jamming scheme in the common scenario, where the intermediate nodes are distributed dispersedly. However, when the intermediate nodes cluster gets close to the sources, it is not superior any more due to the strong interference on the destinations. Therefore, an instantaneous switching between the nonjamming scheme and the jamming scheme is proposed to avoid the negative interference. The hybrid scheme is validated to well improve the secrecy performance of DF two-way relay networks via simulation analyses.