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This paper investigates the security and data reliability in Unattended Wireless Sensor Networks (UWSNs). We deduce an analytical model for Self-Healing scheme based on Cluster Controlled Mobility (SH-CCM) for UWSNs. The SH-CCM is based on mobility inside a cluster of sick sensor beside the hybrid cooperation from both reactive and proactive peers to enhance self-healing probability. The analytical analysis of SH-CCM will ensure that both mobility and hybrid cooperation from both reactive and proactive peers within the cluster of sick sensor will enhance the Cooperation, Self-Healing, data security and reliability. Therefore, the proposed SH-CCM scheme will help the sick sensor to self-heal and restore its backward secrecy faster and better than the schemes without controlled mobility. A set of Analytical results are carried out to demonstrate the effectiveness of the proposed SH-CCM scheme in the presence of an Adversary (ADY). The obtained results ensure that the proposed scheme has a better performance; it archives a probability of BSe to be compromised of 0.04 while CHSHRD [1] is 0.065.

One of the main constraints in wireless sensor networks (WSNs) is the energy consumption. To mitigate this limitation and to prolong network life-time, stability period and throughput, this paper proposes new cluster-heads selection protocols, they based on Stable Election Protocol (SEP) and Distributed Energy-Efficient Clustering (DEEC). We first propose Enhanced Zonal-SEP (EZSEP) and Zonal Threshold-DEEC (ZTDEEC) protocols, the proposed protocols are based on dividing the network field into certain zones, this will improve the connectivity of the far normal nodes with the base station (BS). Several evaluation metrics are used to compare between the proposed protocols and the conventional ZSEP and TDEEC protocols such as: network stability, instability period, life-time and throughput. Considering the same total initial energy, the obtained results show that the proposed EZSEP slightly outperforms the conventional ZSEP in terms of network stability, instability period and life-time, it achieves enormous improvements in terms of throughput as more nodes can transmit direct to BS. On the other hand, the proposed ZTDEEC provides huge improvements in terms of all the evaluation metrics mentioned above. To further improve the network life-time and network throughput, we propose Threshold-based EZSEP (TE-ZSEP) and Enhanced-ZTDEEC (EZ-TDEEC) protocols, in these two new protocols we redefine the threshold formula used in EZSEP and ZTDEEC to consider both weighted energy and weighted distance parameters. By combining the idea of dividing the network field into certain zones and the new threshold formula, the proposed TE-ZSEP and EZ-TDEEC protocols can effectively improve the energy consumption in heterogeneous WSN and prolong its life-time as proved by the obtained results.

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In this paper, a new non-redundant three-layer peak-to-average power ratio (PAPR) reduction technique is proposed for filter bank multicarrier communication based visible light communication (FBMC based VLC) systems. In the proposed technique, the FBMC based VLC data signal is overlapped with two new non-redundant signals. The initial-layer signals are the FBMC modulated signals. For PAPR reduction, the second-layer signals are constructed to decrease initial-layer large-amplitude signals, while the last-layer signals are used to improve the initial-layer small-amplitude signals. The two non-redundant signals do not overlap with the data signals in the frequency domain, because data signals are distributed on odd subcarriers, while even subcarriers are occupied by the constructed signals. To mitigate the effect of large-amplitude signal reduction in the proposed technique, the negative signals are converted into positive, rather than being clipped off as in conventional FBMC based VLC systems. In order to realize a trade-off between PAPR reduction and bit error rate (BER), we introduce a scaling factor in the converted signals. The performance of the proposed technique is calculated in terms of complementary cumulative distribution function (CCDF) and BER. The obtained results indicate that FBMC based VLC systems with the proposed technique can achieve a good trade-off between PAPR reduction and BER and outperforms the corresponding orthogonal frequency division multiplexing (OFDM) based VLC systems.