Social Reliable D2D Relay for Trustworthy Paradigm in 5G Wireless Networks

5G wireless networks envision the usage of millimeter Wave (mmWave) frequencies for a manifold data rates and user capacity increase. However, the inherent line-of-sight (LoS) in mmWave communications raises significant challenges in providing seamless coverage across the dense 5G networks. Device-to-device (D2D) communications offer promising solutions for this LoS challenge by providing relay services. The selection of relay requires maintaining a certain level of trust and confidentiality of the devices. In this paper, we utilize social relationships among devices to form personal trust among different devices. Subsequently, we introduce distributed architecture for social relationships in D2D communications and we discuss new methods for a dynamic social relationship and trust management paradigm. Our analytical models not only show that the proposed scheme achieves 10% - 80% gain in device capacity, 30% - 200% increase in data rates, with approximately 50% less energy consumption over earlier methods, but also discuss co-existence with existing SINR based relay selection schemes. We present temporal dynamics of our social-communication graph using the random graph and Markov process. Our NS3 based 5G simulations demonstrate that our scheme obtains 3 - 5 times more throughput and 50 - 100m coverage extension, with relatively negligible additional delay.