TOT: Trust aware opportunistic transmission in cognitive radio Social Internet of Things

Abstract

In recent years, the Social Internet of Things (SIoT), which represents inseparable relationships between humans and devices, has become a hot research topic in wireless networks. As more heterogeneous devices will be connected, a higher frequency spectrum becomes a requirement. The cognitive radio (CR) technology can improve spectrum utilization in an opportunistic communication manner. However, dynamic spectrum availability and heterogeneous devices complicate routing design in CR-SIoT. Opportunistic routing (OR) can mitigate the drawbacks for routing design of cognitive radio social internet of things, CR-SIoT, by leveraging the broadcast nature of wireless channels; and thereby enhance the network performance. In this work, we propose an energy and trust aware OR in CR-SIoT, which jointly considers energy efficiency, trust and social features. In the proposed scheme, we exploit a new routing metric for selecting forwarding candidates based on optimal stopping theory and use network coding for the data transmission between trusted nodes for multiple types of flows in CR-SIoT. In addition, we propose a game-theoretic approach to allocate the trusted channel for CR-SIoT which is based on expected network gain. Extensive simulation results show that the proposed secure OR protocol performs better than existing routing protocols in CR-SIoT in terms of average energy cost per bit, packet delivery ratio (PDR), network lifetime, average delay, throughput and expected cost of routing.