Networking and Communication Engineering

K. Ilanchezhian ¹, R. Gunasundari ²

Affiliations
1 Department of Electronics and Communication, IFET College of Engineering, Villupuram-60108, IN
2 Department of Electronics and Communication, Pondicherry Engineering College, Puducherry-605014, IN

Abstract

Security is one of the major issues in wireless communication system. In a wireless communication system as the transmission of information signal is over the air, eavesdroppers may have easy access to the transmitted data. The conventional network security mainly depends on cryptographic schemes. But as the security level increases, computational complexity will be high and cause complex key management problems. In this paper, the problem of secret communication between two nodes in the presence of a passive eavesdropper is considered. In general, nodes with multiple transmit antenna elements can ensure secure communication using directional antenna. In this paper, MIMO channel with multiple transmit antenna elements utilize fraction of the available power to produce 'artificial noise' for the improvement of secure communication. The artificial noise is generated by the transmitter in such away that it degrades only the eavesdropper's channel. The various performance metrics such as bit error rate, channel capacity, optimal power allocation and secrecy rate were analyzed in the presence of non-colluding and colluding eavesdroppers. The obtained simulation results are compared with the existing work that does not use artificial noise. It is inferred from the results that the proposed work achieves improved secrecy rate than the existing work.

Keywords

Eavesdropper, Channel Capacity, MIMO, WLAN.

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Thokchom Arvind ¹, R. Gunasundari ¹

Affiliations
1 Department of Electronics and Communication, Pondicherry Engineering College, IN

Abstract

Feedback implosion is a major problem in satellite networks which limits the scalability of satellite networks. As the number of receivers increase the number of feedback messages transmitted by the receivers through the uplink channel increase linearly and hence causes Feedback Implosion. Feedback implosion causes a major part of the system resource to be used up by the transmission of the feedback messages. In this paper, two existing feedback suppression techniques, one employing Game theory, namely Game theory based Feedback suppression and another employing timer-based scheme called the Poker game are combined to get the Hybrid feedback suppression scheme. Here, the receivers’ decision on sending a feedback message is modeled using game theory while the decision for the hold duration for the messages are decided by exponentially distributed timer. Simulation results compare the performance of the three schemes, and it was demonstrated that the new scheme has better feedback suppression capability while still keeping the latency at low levels.

Keywords

Bayesian Equilibrium, Feedback Suppression, Game Theory, Multicast Satellite Networks.

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R. Gunasundari ¹, Gnanou Florence Sudha ¹

Affiliations
1 Pondicherry Engineering College, Pondicherry, IN

Abstract

Recent technological advances in sensors, wireless networking, low power microelectronics, enabled the design and proliferation of wireless sensor networks in human health care monitoring systems. As health care data transmission is a very critical application, high reliability is required in order to avoid fault diagnosis. The concept relaying is incorporated in order to ensure reliable transmission from the source to destination thereby increasing the throughput. The transmission and reception of ECG signal alone is considered in this paper. Performance is analysed by using Amplify and Forward and Decode and Forward relaying protocols. To overcome the energy consumption problem, a new approach for selection of relays is proposed based on the critical distance as a condition. Further, this relay selection is applicable for realistic non linear battery model which has not been considered in relay networks so far. In non linear battery model, the relay can be located arbitrarily. Thus, is approach enables to transmit the data in energy efficient manner and ensures high reliability.

Keywords

Health Care Monitoring System, Relaying, Wireless Sensors, Performance.

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R. Gunasundari ¹, Choragudi K. Y. Karthik ¹

Affiliations
1 Pondicherry Engineering College, Pondicherry, IN

Abstract

To cope with the recent reality of stringent shortage in frequency spectrum due to the proliferation of wireless services, cognitive radio has been considered as an attractive technique to improve spectrum utilization for future wireless systems. In such an environment, secondary user opportunistically accesses the spectrum which requires efficient spectrum sensing technique to ensure a good service to both primary and secondary users. Many methods are proposed in the literature in the area of spectrum sensing. However the performance of these methods deteriorates if proper information of the primary user channels is not available. Security issues in cognitive radio networks are attracting more and more studies in recent years. The success of cognitive radio networks, however strongly depends on counteracting such potential security attacks and threats. Primary user emulation attack (PUEA) is one of such serious attacks. Hence this paper proposes an algorithm called „blind‟ spectrum sensing based defense strategy which performs even when the noise variance is uncertain or unknown. This paper proposes a scheme to characterize an advanced primary user emulation attack and an advanced countermeasure against it.

Keywords

Blind Spectrum, PUEA.

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